1. Field of the Invention
The present invention relates to a bonding tool, an electronic component mounting apparatus and an electronic component mounting method for mounting electronic components on a circuit board or the like.
2. Related Art of the Invention
There are various known methods for bonding electrodes of electronic components to electrodes on a circuit board. For example, ultrasonic bonding is one such bonding method which is capable of bonding electronic components to a circuit board in a short time.
The ultrasonic bonding method uses ultrasonic vibrations to vibrate an electronic component held by an electronic component holder heated by a heater while pressing the electronic component against a circuit board to electrically bond electrodes of the electronic component to electrodes on the circuit board.
Referring to FIG. 11, a configuration and operation of a conventional electronic component mounting apparatus that uses the ultrasonic bonding method will be described.
FIG. 11 is a schematic front elevation view of a conventional electronic component mounting apparatus.
The conventional electronic component mounting apparatus includes a bonding tool 9003 holding an electronic component 1, a circuit board holding unit 9006 holding a circuit board 2, and a pressing unit (not shown) pressing the electronic component 1 held by the bonding tool 9003 against the circuit board 2 held by the circuit board holding unit 9006 (see for example WO2007/129700, in particular p. 1 and FIG. 6).
The entire disclosure of WO2007/129700 is incorporated herein by reference in its entirety.
The bonding tool 9003 includes a component mounting unit 9030, a leg 9312, a supporter 9005, and a heater holder 9324. The leg 9312 and the heater holder 9324 are separately formed and apart from each other.
The component mounting unit 9030 includes a horn 9031, an ultrasonic transducer 9004, and an electronic component holder 9009.
The horn 9031 is a unit which transmits ultrasonic vibrations and has a heater insertion hole 9311 in which a heater 9033 is inserted with a predetermined clearance from the wall of the heater insertion hole 9311. The ultrasonic transducer 9004 is a unit which is fixed at one end on the +X side of the horn 9031 and produces ultrasonic vibrations. The electronic component holder 9009 is a unit fixed on the other end of the horn 9031, holds the electronic component 1, and is heated by the heater 9033.
The supporter 9005 supports the leg 9312 and the heater holder 9324.
The leg 9312 holds the horn 9031 at the nodal point P0 of ultrasonic vibration of the horn 9031 across the horn 9031 from both +Y and −Y sides of the horn 9031.
The heater holder 9324 holds the heater 9033 across the heater 9033 from both of the +Y side and −Y side of the horn 9031.
The electronic component 1 held by the bonding tool 9003 is pressed against a circuit board 2 by the pressing unit (not shown) and heat and ultrasonic vibration are applied at the same time to the electronic component 1. Electrodes of the electronic component 1 are bonded to electrodes on the circuit board 2 by using the heat and ultrasonic vibration.